I have now seen the light and will not do a stupid thing like that.
This is great news, I think you should pop in for a coffee or a beer or a brandy in any event! What area in Pta are you in?
@Swartkat @JacoDeJongh To help the thread and maybe later subscribers please flesh out “the light” for us 
mmaritz, why is your voltage so low at 50 with an SOC of 60%?
Come again about what I should do about the light that I’ve seen? 
Pizza and beers works too.
I’m keen for us to document the reasons for NOT paralleling on the roof (ie access, fusing issues etc.)
I have a Pylontech battery bank so 15s not 16s. So a lower voltage
It’s fully charged at 53.2V
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Aaah. Give me time to do little write up which will be understandable for folks like me. Much of the things you clever guys talk about are way over my head, but I do catch on in the end.
The problem clever folk have (with the utmost respect off course) is that they find it difficult to explain to the dummies like me what is going on. But my experience of this forum is that this is a “safe space” lol, and I can comfortably ask my questions.
Like your Pylontech cell amount just now, I just learned something new, thanks!
Not everyone can explain complicated concepts to dummies.
It is a safe place here. I’m a dummy and I’m here.
And then some have 18 cells. T&C’s apply.
What is your charged voltage again @TheTerribleTriplet 62V?
18 x 3.45v = 62.1v
Float at 3.375v per cel = 60.75v
NOTE:
This is for Victron inverters only.
BMS must also be able to handle 66v min.
To be clear, there is nothing wrong with combining strings on the roof. But then you need a combiner box (a water tight one) on the roof. So it makes sense only when the combiner box, and the resulting thicker cable from the roof, costs less than the alternative. In other cases, having the individual strings below makes it so much easier to fault find without even having to get on the roof.
Edit: To be even more clear, by “combiner box” I mean a small distribution box with fuses, breakers, all the stuff you normally put downstairs, places on the roof in an accessible place, because it makes more sense to run less actual copper to your central “string” inverter. Frequently done in large commercial installs, but in this case it will cost more than an extra pair of cables.
One of the reasons I’m running out of space. My panels are on my garage roof which is very easily accessible as I walk flatfooted between the panels and move them around as I please.
I have a hell of a lot space left on my main roof, but that’s a different kettle of fish involving installation cost that will break the bank as it is 3 storeys high and very difficult to get to. I’d need a crane of sorts or a helicopter to take the panels up!
And this dummy…combined the 6 strings on the roof itself without a combiner box, and merely taped the connections water tight with that self fusing weather tape. It seems to work so far but a combiner box is on the cards in the near future.
You can get these and fuse each of your strings.
Yup, you can often rent one for the day, but they don’t come cheap, and you are often expected to pay upfront, while the crane delivery guy may only deliver it by 11AM… true story.
But there are also these kinds of things:
Although, you do need a rather good and properly long ladder for that to work. And washing the panels becomes another chore.
If you can get away with them at a lower level… absolutely do that.
Now that’s quite clever, because MC4’s are already waterproof!
This was my reasoning yes, especially for cleaning them. My house looks like that, the difference being that it is actually a 2 storey flat roof, over which I had an corrugated iron roof constructed (about the height of a 3rd storey) as I was sick of water ingress. The iron roof though overlap the normal roof. So this ladder move will be very tricky and dangerous. I will not attempt it myself.
At some point, the cost of putting a ground mount next to the house, and trenching cabling, starts to look more attractive than putting panels on THAT roof.
Quite clever using a vertical winch/hoist like that! Even more so if you could build it yourself.
I actually lied. My garage has a little afdak over my short driveway towards the road. Plenty of space there for easily another 5 Kw PV array.
But these panels would be clearly visible to everyone and their dog in the street, and to access this roof you need merely stop a vehicle close to my gate. And once you’re on the afdak, you’ll see all current array as well on the garage…
So no. No more roof space left!!! 
Must add, that tried and trusted installers have learned some pretty clever ways to get things done, irrespective of the roof type, slope, or height.
Just saying.